The invention generally relates integrated circuit (IC) testing, and more specifically to a package on package thermal forcing device.
In general, package on package (PoP) is an integrated circuit packaging method to combine vertically discrete logic and memory ball grid array (BGA) packages. Two or more packages are installed atop each other, i.e. stacked, with a standard interface to route signals between them. This enables higher component density in devices, such as mobile phones, personal digital assistants (PDA), and digital cameras.
During testing of integrated circuits (ICs) in a PoP format, it is necessary to control both a top package (e.g., memory) and a bottom package (e.g., logic) at a temperature to validate proper operation of the ICs in extreme environments. However, prior approaches only enable control of the logic device (i.e., the power generator) through the memory and test contactor interposer. Controlling the logic device is extremely inefficient due to a thermal impedance through the top device and the interposer.